Dryer cylinder with an air impinging hood



DCC- 29, 1964 R. R. MCKELLAR ETAL 3,163,503

DRYER CYLINDER WITH AN AIR IMPINGING HOOD FRANK HAYNES ATTORNEYS Dec. 29, 1964 R, R MCKELLAR ETAL 3,163,503

DRYER CYLINDER WITH AN AIR IMPINGING HOOD Filed Aug. 15, 1960 4 Sheets-Sheet 2 FIG-2 ROBERT R. MGKELLAR, am am. NVENTORS JOSEPH wlcouTuRE e.

FRANK HAYNES BWMMRW AT TO RN EYS Dec. 29, 1964 R. R. MCKELLAR ETAI.. 3,163,503

DRYER CYLINDER WITH AN AIR IMPINGING Hoon Filed Aug. l5, 1960 4 SheetS-Sheet 5 FIG-4 Il@ f: 4o\` 1?(,1 5 @o H5 z nl a ROBERT R. MGKELLAR, Jg mu s 'NVENTORS JosEPHwcouTuRE a FRANK HAYNEs BYMMMW ATTORNEYS Dec. 29, 1964 R. R. MOKELLAR ETAL 3,163,503

DRYER CYLINDER WITH AN AIR IMPINGING HOD Filed Aug. 15, 1960 FIG-6 f 4 Sheets-Sheet 4 nk-825 T IIHHIIIIHHH M l im: Llo@ 9o ROBERT RMGKEL JOHN n. LYNCH GEORGE R. MARH,

Joss-:PH w.cOuTuRE a INVENTORS FRANK HAYNES ATTORNEYS United States Patent v 3,163,503 DRYER CYMNDERWETH AN Am lMPiNtGlNG HGD Robert R. McKellar, Kettering, Jhio The Black- Clawson Company, Air Systems Division, Hamilton, Ohio); .lohn D. Lynch, 'fhe Slack-@lawson Company, Diits Division, Fulton, NX; George R. Marsh, 19381 Valencia Road, Largo, Fia; Soseph W. Couture, rEhe Black-@lawson Company, llilts Division, Fulton, NSY.; and Frank Haynesrc The Mach-@lawsuit Company, Paper Machine Division, Watertown, Filed Aug. l', lgtl, Ser. No. 49,599 I d Claims. (Cl. 3ft-122) This invention relates to paper web dryers, and more particularly to a hot air dryerfor use in conjunction with a dryer shell to remove moisture from a moving web of paper.

The dryer of this invention is constructed of a plurality of separate modules or units arranged and mounted in contiguous relation one to the other to form a completed dryer. The dryer is mounted transversely to a moving web of paper to direct heated air in impinging relation against the surface of such a web moving over a dryer shell. The combined dryer units are supported on a litting frame for initial alignment with the shell and for twoway Vadjustable radial movement `relative. to the shell. The arrangement of the lifting frame provides a dryer having uniform and constant clearances between the dryer units and the shell.

The individual units which make up the complete dryer each include an arcuate nozzle assembly incorporating nozzles for directing heated gases into impingement with the paper, and'return openings for the withdrawal of moist air from the region between the nozzle assembly and the web. The nozzle assembly is connected to a supply duct portion ofthe unit preferably through a variable damper, and the return openings are similarly connected to a return duct through a variable damper. The dampers are adjustable to regulate the rate of hot air application to the web therebyproviding control of the drying etect of each individual unit at arcuate segments of the shell. Each of the adjacent units is preferably similarly provided with dampers to provide for proile control of the moisture content of the moving web.

The position of the air dampers may be manually Vor remotely controlled, and remote control visconveniently effected through a separate air piston and bellcrank assembly for each unit, for the simultaneous movement of a pair of damper plates. The supply and return duct portions of the individual units open into similar portions of adjacent units to form common'supply andreturn passageways which are connected at the inner end of the dryery to the usual heated air supply and return ducting.

The lifting frame for moving the assembled dryer units radially toward and away from the shell includes a pair of spaced apart support rails mounted at opposite ends on screw jacks. The jacks are mechanically interconnected to each other and provide for leveling vadjustment of the four corners of the dryer as well as for uniform raising and/lowering movement by reason ofthe niechanical interconnections. i' p V The individual units are lsupported on the rails and are held in contiguous relation by tie bolts providing for eX- pansion with heat in the longitudinal direction with the rails. The width of the individual units is such as to provide effective control of the drying of a web adjav cent a segment of the shell in order to compensate for the effect of air escape at the edge, and to provide uniform drying of the web. The dryeror" this invention is characterized by high air capacity and ethciency, and is adapted n of units or by the closure of the dampers of existing units.

It is therefore Va principal object of this invention to provide a dryer as outlined above characterized by versatility and high drying capacity.

A further object of this invention is to provide a dryer as outlined above being made up of an assembly of individual units forming common supply and return chambers and each having separately controllable nozzle assemblies.

Another object of this invention is to provide a dryer as outlined above having a plurality of dryer nozzle assemblies each of which are individually controllable to proiile the drying of a paper web.

A particular object of this invention is to provide such a dryer including a mounting frame and mechanism for moving the dryer radially toward and away from a shell.

A-still further object of this invention is to provide a dryer having a mechanically interconnected lifting arrangement for the individual leveling and uniform movement of the four corners thereof to establish and maintain a minimum running clearance.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawingsn FIG. 1 is a partially broken away perspective view of a dryer constructed in accordance with this invention;A

FlG. 5 is a section through the unit of FIG. 4 taken generally along the line 5 5 of FIG; 4;

FIG. 6 is a section through the unit of FIG. 4 showing the arrangement of the air dampers taken generally along the line s s of FIG. 4;

FIG. 7 is a section'through one Vof the dampers taken along the line 7-7 of FiG. 4;

FIG. 8 is an enlarged fragment, partially in section, lsDhowing the arrangement of one of the nozzle assemlies;

FIGS. 9a and 9b are sections through the nozzle assembly of FIG. 8 taken respectively along the lines 961-911 and 9b 2b; and.

FIG. l0 is a partial section taken generally along the line Iii-iti of FIG. 2 showing the arrangement of the position limit switch.

Referring to the drawings, which illustrate a preferred embodiment of the invention, a dryer constructed in ac-y cordance with this invention is illustrated in FlG. las including a front support stand ll and a rear support stand 12. The support stands 1l and 12 each include upright legs i3 and i4 connected by a transverse support bar l5. A pair of spaced apart channel-section vsupport rails 17 and l extend between the support bars l5 of the stands il for vertical movement on screw jacks 26. Horizontal lifting'plates 21 are` welded in extending relation adjacent n each' end of the. rails i7 and-i8 for engagement withthe operating head` of the jacks 20.

Y The jacks Ztl are mechanically interconnected to each fother for simultaneous movement by means of a pair of end shafts 22 and 2?,as is best shown in FIGS. 2 and 3.

" The end shafts 22 and Z3 and theassociated jacks A2() are operated through miter drives ,"24 and 2S interconeiiect 'the simultaneous raising and loweringr of the side rails 'i7 and l by the fourscrew jacks 20.' FIG. shows il and l2 and have their opposite ends supported the dryer in typical operative relation with a dryer shell 33, and the position of any one of the jacks may be adjusted by disconnecting the adjacent coupling 34 and turning the jack tothe desired position, to elfect the leveling of the dryer in relation Vto the dryer shell 33.

It will be understood that the arrangement of the support stands 11 and 12 and their relation to the rails 17 and 13 may be Varied without departing from the scope of this invention. For instance, the dryer may be used in conjunction with the bottom portion of a dryer shell rather than the top as illustrated in FIG. 3, and in this case the support stands would support the dryer sections ink inverted relation.

The body of the dryer consists of a plurality of separate dryer units which are mounted in contiguous relation to each other on the support rails 17 and 18 transversely of the associated dryer shell, and each of the units 46 is notched or recessed at 41 on each side to receive the support rails 17 and'18. The units 40 preferably occupy a relatively small portion of the total width of a web on such shell, but the total width of the combined units is at least as wide, and preferably wider than the web to be dried thereby.

The assembled dryer is provided with an outside end unit 45 which differs from the remainder of the units 40 only in the provision of an end closure plate 46 and a pair of inspection doors 47 and 48 which close the end of the supply and return ducts. The inside end unit 40 is arranged to connect with external hot air supply and return ducts 49 and 50 through a quick disconnect coupling 52.

The units 4G are formed of welded sheet metal and The upper portion 60 includes sheet metal side walls 62 and 63 which have inspection openings 64 formed therein, a bottom partition 65 separating the upper and lower portions of the unit 40, and a top 66. The units 49 preferably include insulated sides and tops for the retention of heat energy Lwithin the dryer. v Thus, the top 66 is insulated by fiberglass batting held in place by a finishing cover 67. Side covers 68 conceal the inspection openings 64 and also contain insulation.

The side walls 62 and 63 and the top 66 of each unit 40 are flanged at 69 to receive a high temperature separating gasket between adjacent units. A ilanged divider 70 separates the upper portion 60 into an open supply duct portion 74 and an open return duct portion 75 which are combined with similar portions of adjacentunits to provide common inlet and return passageways for the assembled dryer. The lower portion 61 of each of the units 40 has side walls 77 within which clean-out inspection openings 78 are formed. The openings 78 are covered by insulated side covers 79 similar to the side covers 68 on the upper portion 60.

The lower portion 61 of each of the units 40 includes an arcuately formed, sheet metal nozzle assembly 8i! arranged to overlie a segment of the dryer shell to direct hot gases into impingement with the exposed surface of the paper web, and to Withdraw moist gases from such surface. The nozzle assembly 80 is formed in the lower portion 61 of the unit 40 between enclosingV end plates 83 and 84 and the side walls 77 which, with therpartition 65, enclose the lower portion 61 as a box-like structure.

The nozzle assembly 80 is shown in FIGS. 8 and 9 as being formed with a curved plenum chamber 85 received between the end plates 83 and S4 and communicating with a plurality of air discharging nozzles 90. The nozzles 9.0 are essentially wedge-shaped as viewed from the end, and fan-shaped from the side, as shown in FIG; 9b, and are open at their top into the plenum'chamber 85. The outlets 91 of the nozzles 90 form longitudinal slits substantially the depth of the unit which align with the slits of similar nozzles in adjacent units. The

upper portion of the nozzle assembly 80 forms a neck 92 which opens into the hot air supply 'duct '74 through an inlet opening 95 formed in the partition 65. Several curved deflectors 96 may be placed in the neck 92 to aid in the distribution of air from the opening 95 to the nozzles 90.

The nozzles 9i) are arranged to direct the hot air from the inlet duct 74 into impingement with the surface of a web on the dryer shell 33. Pairs of end nozzles 97 are arranged to direct air inwardly and somewhat tangentially to the web to reduce the loss of air along the entrance and exit edges of the dryer.

The nozzle assembly 8? further includes a plurality of openings 1% disposed in rows betwen the nozzles 90 for the removal of moist air from the zone adjacent the surface of the web. These openings 100 communicate with the interior of the lower portion forming a return air chamber 1411 which interior is in turn opened into the return duct 75 at arreturn opening 102 formed in the partition 65. Larger openings 163 are formed adjacent the entrance and the exit edges of the dryer outwardly of the inclined nozzles 97 for the purpose of collecting moist air at these regions with the reduction of air loss along the edges of the dryer.

Adjustable means are associated with the nozzle assemd blies of each of the units for controlling the rate of hot, air now to the nozzles and the rate of return from the` openings 100 and 103. More specifically, a first damper plate 165 is slidably mounted on the partition 65 and selectively movable to cover the inlet opening 95, and a second damper plate 106 is similarly situated with respect to the outlet opening 102. As shown in FIGS. 6 and 7, the plates and 106 are arranged for sliding movement within damper guides 108 fixed to the partition 65, and are interconnected for concurrent adjustment by a damper or tie rod 110. The rod 110 is secured to the damper plates by means of nuts 111 welded to the upper surfaces of the plates, and is arranged to move transversely of the dryer through a tubular guide bushing 112 in the wall 62 and a similar bushing 115 in the divider 70.

Thedamper plates may be remotely controlled by means of a damper unit assembly including a diaphragm-operated air motor 115 suspended on a hangar bracket 116 secured to the top of each of the units 40. The motor 115 is arranged to have air pressure extending action and spring return to position the damper rod 110 and the attached damper plates through a bell crank 117 and a clevice pin 118 attaching the bell crank to the rod 110.

It is understood that the inlet and outlet dampers may be manually-adjusted where automatic moisture control or remote positioning is not desired. Either manual or remote control may be employed to provide for the profile control of the moisture content of the moving web by conj trolling lthe rate of hot air application and moist air with- Vrouudness, of the dryer shells.

drawal at transverse arcuate segments of the dryer shell.

The operation of the dryer is further controlled through a position limit switch arrangement for defining the maximum open position of the assembled units 40 on the side rails 17 and 18 for threading and the closed or lowered position of the units for drying. Referring to FIG. 10, a bracket 120 is mounted on one of the transverse support bars 15 and extends upwardly therefroml adjacent the channel rail 18. A pair of limit switches 121 and 122 are ad justably mounted on the bracket for engagement with a cam 124 carried on the adjacent rail 18 to define the limits of radial movement of the dryer shell. As an example, it has been found that a 9inch rise provides clearance suf- Vicient for threading purposes. ,The uniform operation provided by the jacks 20, including their direct mechanical interconnection, permits a minimum running clearance in the order of 1A to of an inch, this being dictated by the Such minimum clearance is readily obtained once the limit switches 121 and 122 have been properly adjusted afterreach subsequent thread. ing of the dryer.

The number of the units 4d making up the dryer body for a given installation is dependent upon the width of web to be dried. The width of the individual units is preferablyV such that permits elfective vcontrol of the moisture content transversely of the web through the adjustable dampers, and a unit width of 12 inches has been found satisfactory, as anexample.

The units tu are placed in contiguous relation on the rails 17 and 18 to form the dryer body and are separated by high temperature gaskets at the end plates d3 and at the iianges 69. A plurality of tie bolts 13u are extended through tie bolt openings formed by short sections of tubing 131 through the units 40 and extend to receive retaining nuts 132 and springs 133, as shown in FIG. 1. The tie rods 13@ and springs 133 provide for the expansion of growth ofl'the dryer body with the rails while providing for a constant seal between the units with contraction and expansion.

In the operation of the dryer, the motor 3d is operated to rotate the screw jacks. 2d through the rniter drives 24E-2.5 and shafts to apply a uniform rate of rise at the four corners of the dryer defined by the plates 21, thereby moving the assembled'units tu radially outward from the dryer shell. The upper limit'switch 121 may be adjusted to deiine the extent of this movement, as desired.

After threading in the usual manner, the reversible motor 30 may be again energized lto lower-the dryer into its operative position. Anyuneveness of the dryer with respect to the dryer shell may be initially compensated for by the loosening of the couplings 34 and the individual rotation of the screw jacks 2d, as necessary. The lower limit position will therefore be maintained with accuracy throughout the subsequent use of the lifting mechanism, and the lower limit switch l2?. may he adjusted to cause the dryer to return to the desired working position.

Hot air from a suitable furnace is applied under pressure through the external inlet duct 49 to the inlet supply passageway defined by the inlet duct portions 74- or" the several units. This hot and dry air is then applied to the moving surface of web through the adjustable inlet 95 and the nozzles 9i) and 97. Moist air is withdrawn from the surface through the openings lltlt and lii through the adjustable outlet opening 102 and the outlet passageway in the dryer deiined by the outlet ducts 7S.

The insulated cover 67 and sidepanels d and 79 serve to retain much of the heat energy within the dryer, and such side panels are removable to provide access into the dryer units for cleaning. Also, the doors il? and d8 provide access for cleaning, adjustment, and maintenance purposes. The inlet and outlet dampers may be adjusted, as desired, to provide predetermined drying results such as proiiling, and this maybe accomplished either through limit or automatic control.y

While the form of apparatus herein V.described constitutes a preferred embodiment of the invention, it is to be understood that Vthe .invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the inf-'ention which is defined in the appended claims.

Whatis claimed is:

l. A dryer unit adapted for use with a plurality ofsimilar units in contiguous relation to form a complete dryer for removing moisture from a moving webo paper, comprising an upper portion and alower portion separated return air chamber arranged to receive moist air from said openings, means in said upper portion forming a segment of a hot air supply duct and a segment. of a moist air return duct, a first variable damper positioned in said partition between said supply duct segment and said plenum chamber to regulate the rate of air flow from said duct through said nozzles and a second variable damper connected for movement with said lirst damper and positioned in said partition between said return duct segment and said return air chamber to regulate the moist air return rate through said openings.

2. A dryer for removing moisture from a moving web of paperV passing over a drying shell, comprising a pair of longitudinallyextending support rails adapted to be positioned adjacent the shell on opposite sidesfthereof, a plurality of separate drying units mounted in contiguous relation on said rails and having a total width at least as Wide as the web, means in each said units for directing hot gases into impingement with the web and for removing moist gases therefrom, rod guide tubes transversely posii tioned in each of said units and arranged to be in alignment with similar tubes in adjacent units in said contiguous relation to form transverse tie rod openings, tie rods received in said openings and arranged to extend through the combi-ned width of said units, and retaining means on the extended ends of said tie bolts for holding said units in compression and providing for the expansion thereof upon heating.

3. A. dryer for removing moisture from `a moving web of paper passing over a drying shell, comprising a plurality of separate drying units mounted in contiguous relation transversely of the shell and having a total width at least as wide as the web, means in each said units for directing hot gases into impingement with the web and for removing moist gases therefrom, rod guide tubes transversely positioned in each of said units and positioned for alignment with similar tubes in adjacent units in said contiguous relation to form transverse tie rod openings, tie rods received in said openings and arranged to extend through the combined width of said units, nuts on the extended ends of said tie rods, and compression springs interposed between said nuts and the adjacent said unit to hold said units in compression one against the other and to provide for the expansion thereof upon heating on said tie rods.

4. A dryer for removing moisture from a moving web of paper passing over a drying shell, comprising a pair of longitudinally extending spaced apart support rails adapted to be positioned adjacent such shell on oppositesides thereof, a dryer body mounted on said rails and having a width at least as wide as the web, means in said body for directing hot gases into impingement with the web and for removing moist gases therefrom, a pair of support stands positioned adjacent each end of said rails and having a mechanical screw jack positioned in lifting relation to each end of said rails, mechanical means interconnecting said jacks for simultaneous operation to move said dryer body radially inward and outward in relation to the shell, and means for separately adjusting .each of said jacks` for the initial leveling of said dryer body in relation to the shell.

by a partition, an `arcuately shaped nozzle'assembly in said lower portion adapted tovbe positioned adjacent a segment of a vdryer shell for removing moisture from 'a web on such shell and having a plurality of nozzlesA arranged to impinge heated air against the exposed surface of such web, said assembly further having means in said lower portion deininga plurality of openings for withdrawing'moist air from adjacent the surface of the web,

means in said lower portion defining a hot air plenum chamber connected to supply air to said nozzles and a 5. A dryer for removing moisture from a moving web of paper passing over a drying shell adaptedfor easy threading and accurate return to a predetermined drying position, comprising a pair of longitudinally extending..

support rails adapted to be positioned adjacent such shell on opposite sides thereof, a dryer body mounted on said rails and having a width at least as wide as the web, means in said body for directing hot gases into impingement with the web and for removing moist gases therev Y from, support means positioned adjacent each end of said rails and having a mechanicalscrew jack positionetl in lifting relation to each end'of said rails, mechanical means interconnecting said jacks for simultaneous operation to move said dryer body radiallyY inward and outward adener-1350s 7 jacent the shell between a drying position and a threading position, each of said jacks being separately adjustable for the initial leveling of said dryer body in relation to the shell, and limit switch means having arconnection to said support having adjustable means for limiting the inward movement of said body to a predetermined drying position with controlled and predetermined running clearance.

6. A dryer for removing moisture from a moving web of paper passing over a dryer shell, comprising a plurality of separate drying units each having a width forming a small part of the total width of the web and supported in contiguous relation to each other transversely of the web and with a total width at least as wide as the web, means in each of said units forming a segment of a hot air inlet duct which is open at least on one end of said unit with the opening in alignment with similar said duct segments of adjacent units to form a common hot air passageway, a separate arcuate nozzle assembly forming a part of each of said units arranged to overlie a corresponding segment of the shell and connected to receive air from said inlet duct segment and to direct air in impinging relation against the exposed arcuate surface portion of a web on such shell, each of said units including further means forming a segment of a moist air return duct being open at least on said one end thereof with the opening in alignment with similar duct segments of adjacent units forming a common return air passageway for said dryer, means in said nozzle assembly arranged to receive moist air adjacent said web and opening into said return duct segment, and internal controllable damper means in each of said units positioned between said nozzle assembly and said inlet duct segment for controlling the rate at which hot air is admitted into said nozzle assembly.

7. An individual dryer unit adapted for use in combination with a plurality of similar units arranged in contiguous transverse relation to a dryer shell to form a complete dryer for removing the moisture from a moving web of paper on such shell, comprising a sheet metal body v 8 having a width forming a small part of the total width of the web to be dried, said body having an upper portion closed on the top and sides thereof and having vat least one open end facing transversely of such web for alignment with similar openings in adjacent said units, said body further having a lower portion separated from said upper portion by a partition, said lower portion including an arcuately shaped nozzle assembly adapted for positioning adjacent a segment of such dryer shell having a plurality of nozzles arranged to impinge heated air against the exposed surface of said web, said assembly further having means defining a plurality of return openings for withdrawing moist air from adjacent the surface of the web, said nozzle assembly further including a hot air plenum chamber formed in said lower portion and opening into said upper portion at one side thereof, divider means in said upper portion forming a hot air duct segment in communication with said plenum chamber and a moist air return segment in communication with said moist air return openings.

S. The dryer unit of claim 7 comprising means in said body defining a pair of opposite recesses positioned substantially midway between the top and bottom thereof at said partition for mounting on a pair of parallel support rails.

References Cited in the file of this patent UNITED STATES PATENTS Daane May 14, 

1. A DRYER UNIT ADAPTED FOR USE WITH A PLURALITY OF SIMILAR UNITS IN CONTIGUOUS RELATION TO FORM A COMPLETE DRYER FOR REMOVING MOISTURE FROM A MOVING WEB OF PAPER, COMPRISING AN UPPER PORTION AND A LOWER PORTION SEPARATED BY A PARTITION, AN ARCUATELY SHAPED NOZZLE ASSEMBLY IN SAID LOWER PORTION ADAPTED TO BE POSITIONED ADJACENT A SEGMENT OF A DRYER SHELL FOR REMOVING MOISTURE FROM A WEB ON SUCH SHELL AND HAVING A PLURALITH OF NOZZLES ARRANGED TO IMPINGE HEATED AIR AGAINST THE EXPOSED SURFACE OF SUCH WEB, SAID ASSEMBLY FURTHER HAVING MEANS IN SAID LOWER PORTION DEFINING A PLURALITY OF OPENINGS FOR WITHDRAWING MOIST AIR FROM ADJACENT THE SURFACE OF THE WEB, MEANS IN SAID LOWER PORTION DEFINING A HOT AIR PLENUM CHAMBER CONNECTED TO SUPPLY AIR TO SAID NOZZLES AND A RETURN AIR CHAMBER ARRANGED TO RECEIVE MOIST AIR FROM SAID OPENINGS, MEANS IN SAID UPPER PORTION FORMING A SEGMENT OF A HOT AIR SUPPLY DUCT AND A SEGMENT OF A MOIST AIR RETURN DUCT, A FIRST VARIABLE DAMPER POSITIONED IN SAID PARTITION BETWEEN SAID SUPPLY DUCT SEGMENT AND SAID PLENUM CHAMBER TO REGULATE THE RATE OF AIR FLOW FROM SAID DUCT THROUGH SAID NOZZLES AND A SECOND VARIABLE DAMPER CONNECTED FOR MOVEMENT WITH SAID FIRST DAMPER AND POSITIONED IN SAID PARTITION BETWEEN SAID RETURN DUCT SEGMENT AND SAID RETURN AIR CHAMBER TO REGULATE THE MOIST AIR RETURN RATE THROUGH SAID OPENINGS. 